The present invention relates to a circuit device for controlling the pilot voltage applied to the solenoid of an electromagnet associated with an electric starter motor for an internal combustion engine of a motor vehicle.
The electromagnet, which is typically associated with an electric starter motor for a motor vehicle, is intended to cause a drive pinion to mesh with the teeth of a rotatable member (ring) of the internal combustion engine just before the starter motor is energised to cause rotation of the pinion. To this end the movable core of the electromagnet is coupled to a lever which controls displacement of the pinion.
Upon each starting operation a piloting voltage is applied to the solenoid of the electromagnet and the movable core translates by the effect of the field generated by the solenoid and, via the lever, urges the pinion towards the starter ring of the internal combustion engine.
In order to reduce the violence of the impact of the pinion against the starter ring of the internal combustion engine it is desirable to be able to control the speed of displacement of the said movable core.